The field of this invention relates to solenoid actuated fluid control valves and more particularly to a pneumatic valve that can supply various preselected pneumatic pressures.
Solenoid actuated valves for controlling the flow of pneumatic fluid have long been used to supply a preselected pneumatic pressure for various tools. Furthermore, various tools such as welding tips have been connected to a plurality of valves with each valve controlling a different pneumatic pressure such that the tool can be more adaptable and used for a range of purposes.
In the past, each pressure valve assembly was custom built with a customized manifold and circuit board for controlling the various solenoid valves. If a different pressure level is later to be added, the entire manifold and circuit board needed to be replaced to accommodate the additional pressure level.
These valves often include a relieving regulator to control the pressure level. When the pressure is lowered, the pneumatic pressure is relieved through bleeding of the relieving regulator. The bleeding through the relieving regulator is a relatively slow way to relieve pressure down to lower pressure levels. The slow bleeding process prevents rapid changes of pressure levels and limits the use of these valves to environments where rapid pressure changes are not necessary.
What is needed is a pressure selector valve assembly that is modular in construction for allowing an adjustment in the number of selected pneumatic pressure levels for the gas supply and also provides for a rapid change in the selected pressure.
In accordance with one aspect of the invention, a control valve assembly for supplying a choice of preselected pressure levels from a pneumatic supply includes a manifold connectable to a common primary pneumatic pressure. First and second regulators are mounted onto the manifold. Each regulator has an inlet for receiving pneumatic pressure from the common primary pneumatic pressure. Preferably, first and second regulator supply passages extend from the primary supply to each regulator. The first and second regulators have an outlet for providing respective different first and second lower secondary pressures to an electrically actuated selector valve that is mounted onto the manifold.
It is desirable that the manifold has respective intermediate passageways for receiving the outlet pressure from said respective regulators and passing the pneumatic pressure onto the inlets of the selector valve. Preferably, the manifold has two opposite sides with an outlet side having a supply passage port, an exhaust passage and a discharge passage therethrough. The manifold inlet side has a supply passage port and inlet port for receiving pneumatic pressure. It is desirable that the primary supply passage and the exhaust passage are in the form of galleries that pass directly through each manifold.
The selector valve includes a housing with two inlet ports, two outlet ports and an exhaust port connected to a valve chamber and at least one valve element operably mounted in the chamber. The selector valve is movable to a selected one of two positions based on the electrical actuation or de-actuation of the selector valve such that a respective inlet port is connected to its respective outlet port and the other inlet port is closed from its respective outlet port which in turn is in communication with the exhaust port.
It is desirable that the selector valve is a solenoid actuated spool valve. The inlet ports of the selector valve are in fluid connection with the respective outlet ports of the regulators for supplying the respective pneumatic pressures to the selector valve. The respective outlets of the selector valve are connected to respective inlets of a shuttle valve. The shuttle valve has a single outlet selectively in communication with one of its respective inlets that contains a higher pneumatic pressure therein. The exhaust port of the solenoid actuated selector valve is in communication with the exhaust passage in the manifold. The outlet port of the shuttle valve is in communication with a discharge passage in the manifold for receiving a selected one of the secondary pressures from the respective regulators via the selector valve.
Preferably, the shuttle valve has a housing mounted in an interposed position between a respective selector valve and the respective manifold. The shuttle valve housing has an exhaust passage that connects the exhaust port of the selector valve to the exhaust passage in the manifold.
In accordance with another embodiment of the invention, a modular pneumatic pressure control valve assembly for supplying a choice of pre-selected pressure levels from a pneumatic supply includes an actuatable selector valve mounted onto the manifold. The selector valve includes a housing with two inlet ports and two outlet ports connected to a valve chamber and at least one valve element operably mounted in the valve chamber. The valve element is moveable to a selected one of two positions based on the electrical actuation or de-actuation of the valve such that a respective inlet port is connected to its respective outlet port and the other inlet port is closed from its respective outlet port. The first manifold is connectable to a second manifold. The second manifold has an auxiliary regulator mounted thereon for regulating pneumatic pressure from the primary supply passage. The second manifold also has a secondary inlet port in communication with the discharge passage of the first manifold for receiving a secondary pressure from one of the regulators on the first manifold. The auxiliary regulator has an outlet for providing an auxiliary secondary pressure different from said first and second lower secondary pressures.
An auxiliary electrically actuated selector valve is mounted onto the second manifold. The auxiliary selector valve is substantially the same as the selector valve on the first manifold and receives pneumatic pressure from the respective inlets.
The respective outlets of the auxiliary selector valve are connected to respective inlets of an auxiliary shuttle valve which has a single outlet selectively in communication with the inlet of the auxiliary shuttle valve that has a higher pneumatic pressure therein. The outlet port of the shuttle valve is in communication with an outlet passage in the auxiliary manifold for receiving a selected one of the secondary pressures from the respective first, second, or auxiliary regulators via the selector valves.
Preferably, the first and second manifolds are identically constructed with the same passages therethrough. The manifolds have respective first and second intermediate passageways for receiving the outlet pressure from the respective regulators and passing the pneumatic pressure onto the inlets of said selector valve.
The first manifold has its secondary inlet port being sealed by an end plate mounted thereon. The second manifold has its second regulator supply passage and second intermediate passage closed by a mounted sealing plate.
In one embodiment, the first manifold is also connected at an opposite side to a supplemental manifold. The supplemental manifold also has two inlet ports in communication with the primary supply passage. The supplemental manifold has a supplemental regulator mounted thereon for regulating pneumatic pressure from one of the primary supply passages. The supplemental regulator has an outlet for providing a supplemental secondary pressure different from the primary pressure.
A supplemental actuatable selector valve is mounted onto the supplemental manifold. The supplemental selector valve is substantially the same as the selector valve on the first manifold and receives pneumatic pressure from the respective inlets.
The respective outlets of the supplemental selector valve are connected to respective inlets of an supplemental shuttle valve which has a single outlet selectively in communication with the inlet of the supplemental shuttle valve that has a higher pneumatic pressure therein. The outlet port of the shuttle valve is in communication with an outlet passage in the supplemental manifold for receiving a selected one of the secondary or primary pressures.
In accordance with another embodiment of the invention, a multiple pneumatic pressure output valve includes a plurality of manifolds each having at least two intake ports connectable to a supply of pneumatic pressure and two discharge ports. The manifolds are mounted adjacent each other with an outlet of one manifold in communication with a discharge port of a previous manifold. At least one regulator is mounted on each manifold for receiving pneumatic pressure from a respective one of the intake ports and providing respective different lower pneumatic secondary pressures to an appropriate selector valve mounted onto each manifold. The selector valve includes a housing with two inlet ports for receiving the pneumatic pressure from the respective regulators and at least one outlet port connected to one of the discharge ports. A valve element is moveable to a selected one of two positions based on the electric actuation or de-actuation of the valve such that a respective inlet port is connected to an outlet port and the other inlet port is closed.